Encyclopedia of Espionage, Intelligence, and Security

IMINT (Imagery Intelligence)

IMINT, or imagery intelligence, is one of the four major branches of
intelligence, along with HUMINT, MASINT, and SIGINT (human, measurement
and signatures, and signals intelligence respectively). Formerly known as
photographic intelligence, or PHOTINT, IMINT is derived from photography,
infrared sensors, synthetic aperture radar, and other forms of imaging
technology. It was this wealth of imagery sources and techniques that
influenced the
shift in terminology from PHOTINT to IMINT during the 1970s.

Collection platforms for IMINT have ranged from surveillance balloons,
employed from the time of the French Revolution onward, to satellites such
as those of the KH or KEYHOLE series. In addition to KEYHOLE, CORONA, and
other satellite systems employed by U.S. intelligence, there are
satellites that are not obviously tasked for intelligence gathering.
Aircraft, both manned and unmanned, have long served in the mission of
gathering IMINT. These range from the B-17 Flying Fortress of World War II
to the U-2, in use since the 1950s, to Pioneer Unmanned Aerial Vehicles
used in the Persian Gulf War.

Once gathered, imagery has to be transmitted to processing centers, most
of which are in Washington, D.C. Technicians at the National Photographic
Interpretation Center (NPIC), the National Imagery and Mapping Agency
(NIMA), and other such units are highly skilled at studying photographs
taken from high altitudes or from space. From these images, many of which
would be extremely difficult for the layperson to interpret in even the
most basic sense, imagery technicians can discern information on the
movement of troops and materiel, or other enemy activities.